Apparatus for manufacturing preserved fruits



April 23, 1963 D. J. LIMPERT 3,

APPARATUS FOR MANUFACTURING PRESERVED FRUITS Original Filed Sept. 11,1958 FIG. 2

Overflow FIG. 1

INVENTOR Dean J. Limperf 7. ATTORNEYS United States Patent Ofifice3,086,445 Patented Apr. 23, 1963 3,086,445 APPARATUS FOR MANUFACTURINGPRE- SERVED FRUITS Dean .I. Limpert, Blackwood Drive, Vineland, NJ.Original application Sept. 11, 1958, Ser. No. 760,312, now

Patent No. 3,032,419, dated lWay 1, 1962. Divided and this applicationJuly 13, 1961, Ser. No. 123,698

7 Claims. (Cl. 99239) This invention relates to improvements in themanufacture of preserved fruits of the type in which sugar is stored inthe fruit and more particularly to an apparatus for manufacturingmaraschino cherries.

This application is a division of my US. Patent application Serial No.760,312, filed September 11, 1958, now Patent No. 3,032,419, issued May1, 1962, for Process for Manufacturing Preserved Fruits.

A number of diiferent processes have been proposed for the manufactureof preserved fruits, including the manufacture of maraschino cherries.In general, processes producing satisfactory products are slow andtedious and in many instances take four to six weeks to build up therequired amount of sugar in the fruit. In known processes formanufacturing maraschino cherries, six weeks are required to attain theusual content of 50% sugar.

However, according to some proposals, fruit is impregnated with sugar ina short period of twenty hours or a few days by heating the fruit toboiling and using a hot concentrated hot sugar solution. In one suchproposal a ton of fruit was described as being processed hot in a singlecontainer. But, such processes collapse the structure of the fruit andsoften the tissues resulting in nonuniform products having an appearanceof low quality, particularly with fruits of the type of cherries.

The primary object of the present invention is to provide an improvedprocess and apparatus by which rnara: schino cherries and other fruitscontaining 50% sugar or more are produced in a relatively short periodof time compared to the long periods referred to above.

A further object of the invention is to provide a process and apparatuswhich results in the production of a high yield of maraschino cherriesand similar fruits of the highest quality which are round, plump, tenderand crisp.

A further object of the invention is to provide an apparatus which willovercome the problem of crushing or mashing the fruit during processingand provide a process which will not weaken the cellular structure ofcherries and other fruits.

In accordance with the invention the fruit, for example cherries, afterbeing cleaned, pitted and made ready for treatment. according to knownprocedure, are contacted with an air-free water solution of sugar atordinary room temperatures, advantageously while maintaining thecherries in relatively shallow horizontal layers. The use of suchshallow layers in conjunction with other conditions of the process hasbeen found to prevent crushing and compacting during processing. Thesugar solution is circulated from a sugar dissolving chamber, wheresugar is dissolved by the solution, through the cherries filled intocontainers, for example drums arranged in parallel, and back to thedissolving chamber. In this operation the dissolving chamber or zonecontains a body of sugar solution and is preferably elevated above thedrums of cherries, so that circulation is by gravity and automatic. Thesolution is circulated continuously through the system for a period ofapproximately two to three weeks to complete the deposition of therequired amount of sugar in the cellular strutcure of the cherries orother fruit.

In the initial stages of the operation at least, the solution flowingfrom the containers of cherries to the sugar dissolving zone ispreferably heated sutficiently to cause removal of the absorbed aircontent of the fruit which the solution collects. The solution cools toroom temperature by the time it reaches the fruit in the containers.

During the circulation of the solution through the layers of fruit, aportion of the sugar content of the solution is deposited in thecellular tissues of the fruit by the process of osmosis, the sugarsolution gradually replacing the normal moisture or water content of thefruit. As this replacement occurs, the solution flowing back to thesugar saturating chamber contains about 2% less sugar than the solutionflowing from the chamber to the layers of cherries.

The improved process and apparatus includes other important features andconditions as described more in detail hereinafter in connection withthe accompanying drawings, in which:

FIG. 1 is a diagrammatic elevational view of an apparatus arrangementsuitable for use in carrying out the improved process; and

FIG. 2 is a cross-sectional view taken on the line 22 of FIG. 1.

The apparatus shown diagrammatically in FIG. 1 com prises an open-toppedchamber 10 used for dissolving granulated sugar in the solution beingcirculated in the system. The chamber 10 is provided at the bottom withan outlet pipe 12 which is connected into a header pipe 14, preferablyat about its midpoint. A plurality of connecting pipes 16 connect intothe header 14, and serve to conduct sugar solution in parallelrespectively to the lower portions of processing drtuns 18. An outletpipe 26 is connected into the upper portion of each drum 18, and all ofthese pipes are connected in parallel into a return header 22, connectedby a pipe 24 into a horizontal pipe 26, which at the left, is connectedby a riser pipe 28 into a heating chamber 30 provided with a heatingcoil or unit 32. The upper end of the chamber 32 is provided with anoverflow pipe 34 opening into the upper portion of the chamber 10. Theopposite end of the horizontal pipe 26 is connected into an overflowriser pipe 36 leading to a tank (not shown) and which determines theliquid level in the chamber 10.

The heads of the drums 18 or the ends of the pipes 16 and 20 openingthereinto are provided with perforated plates or screens 38 to preventaccess of cherries to these pipes. The pipes 16 and 20 may be flexibleand are also provided with suitable valves, not shown, so that the drumsmay be disconnected for emptying and refilling or for direct shipping atthe end of a processing operation. Any suitable type of connections maybe provided and removable heads 39 are preferably provided which clampto the drums and facilitate the connection of filled drums into thesystem.

Each drum 18, as shown in detail in FIG. 2, is provided with areadily-removable internal shelf grid structure, so that the cherriestherein are maintained in relatively thin layers not exceeding from 6 to8 inches in depth, with the drums placed horizontally or on a slightincline during processing, as shown in FIG. 1. This grid structurecomprises similar vertically-spaced perforated shelf plates 40 and 42secured to and held in spaced parallel relation with respect to eachother by a vertical plate or plates 44. The shelf plates 40 and 42extend from one end of the drum to the other and to the wall on oppositesides of the drum in a symmetrical relationship, so that the body ofcherries filled into each drum is divided into three superposed layers.In each instance, removable heads are secured so that the solution inletpipe 16 opens into the drum below the lower shelf plate 42, while theoutlet pipe 20 is connected into the drum above the upper shelf plate40. The drums 18 are advantageously set preferably at a slight inclineapproximating 5 to the horizontal, as shown in FIG. 1, favoring the flowof the saturated solution downwardly along the bottom of the drum andthe flow of the more dilute solution upwardly along the top of the drum.

In arranging the apparatus, the headers 14 and 22 are preferably mountedhorizontally and are connected into a considerable number, for exampleforty (40) drums, each of approximately one barrel capacity. The chamber10, having a capacity of about 75 gallons, is preferably set at anelevation with respect to the drums 18, so that there is a difference inelevation between the liquid level in the chamber and the bottom of thedrums of from six to fifteen feet, that is, a difference sufficient toprovide a pressure head adapted to effect automatic circulation in thesystem. In the drawings the direction of flow is indicated by thearrows.

The drums 18 are preferably all at the same level and are convenientlylocated on one floor of the buliding,

housing the equipment, whereas the sugar saturating chamber 10 islocated on the floor above. The saturating chamber 10 is provided with ascreen 46 supported on the upper rim of the chamber 10 and extendingdown into the chamber to a point below the overflow 34. The lower partof the screen has a corrugated formation at 48 to provide an extensivescreen surface in contact with the solution. The screen 46 is of from to80 mesh and adapted to retain granulated sugar, a mount of which isshown at 50. At intervals during the process a IUD-pound bag ofgranulated cane or beet sugar is dumped onto the screen so that a moundof sugar is always maintained on the screen 46 during a run.

In starting up the apparatus as described above, for example for theproduction of maraschino cherries, the

forty drums, or a determined number of drums for the particular run areeach filled with a predetermined weight of prepared cherries, with thedrum heads removed and the removable dividers inserted, the weight beingdetermined by the sizes and characteristics of the cherries. An

important factor in filling the drums is that the drums are t not filledto an extent which would crowd the cherries during processing. After thedrums are filled, they are connected up into the system by securing theremovable heads, then the drums are set in the manner described aboveand shown in FIG. 1 of the drawings. When the drums are all connectedinto the system, it is entirely filled with water until water runs outof the overflow through the pipe 36. At this point granulated sugar isdumped onto the screen 46, the desired flavor and coloring materials areplaced in the chamber 10 and the heater 32 is turned on.

The sugar placed on the screen 46 begins to dissolve through the screenand circulation in the system commences. Since the sugar solution asformed is more dense than the surrounding water, it slowly settles andflows through the pipes 12, 14 and 16 to the drums filled with cherriesand water. This flow forces the water already in the system from thedrums through the pipes 20, 22, 24, 26 and 28, the heater 30 and pipe 34into the kettle or chamber 10. Any excess water in the system and thatreplaced in the cherries overflows through the pipe 36 at the levelindicated.

As the circulation continues, the sugar solution becomes progressivelymore concentrated. For example, during a run, the sugar solutionreturning to the chamber 10 through pipe 34 is only about 1 /2 to 2%lower in sugar content than that of the solution flowing down throughthe pipe 12. In the course of a run of from about 2 to 3 weeks for theproduction of maraschino cherries, the solution flowing through the pipe12 finally reaches a concentration of about sugar. Over the whole periodof a run, the cherries in the drums have a sugar concentration only 2%or less below the concentration of the reinforcing syrup flowing to thedrums 18 from the chamber 10.

The sugar syrup flow is continuous, rapid and level throughout thesystem. For example, the rate of flow through the pipe 34, a 2 inch I.D.pipe, is approximately gallons per hour. As the circulation proceedsduring a run, the sugar is replenished on the screen 46, and theoverflow takes off the water and syrup displaced by the added sugar.During the whole period of the run, there is a continuous flow with theheaviest syrup finding its way to the bottom of the system in the drumswhere the cherries are located, displacing water driven off, as well aslighter syrup which rises to flow back through the heater 30 and drum10, the excess flowing out of the system into tanks through the overflow36.

The heater 30 warms the syrup returning to the kettle or chamber 10 to atemperature of about 140 F. This heating releases the air dissolved bythe water or syrup from the cherries. The warm water or syrup flowingfrom the heater into the kettle or chamber 10 facilitates the dissolvingof sugar from that on the screen 46. The heater 30 has only a smallcapacity, and is not intended to and does not heat the cherries at all,since by the time the syrup is mixed in the chamber 10 and travels thedistance to the drums 18, at the rate of circulation, the syrup iscooled to room temperature.

The heating of the syrup at a particular point in the system, followedby the removal of air from the syrup, gives the syrup an increasedcapacity to dissolve more air as it cools and returns to the layers ofcherries in the drums. The cool, reinforced syrup returning to thecherries in the drums dissolves any air which may be trapped either inthe pit cavities or in the cellular tissues of the cherries. As the warmsyrup gives off its air, when it is delivered into the chamber 10, alayer of foam is formed on the top of the solution in the kettle, whichpersists for about six days during the run. After the air in thecherries has been completely removed, the foam on the kettle subsidesand the syrup becomes crystal clear. The processing continues for theentire run, gradu ally and imperceptibly increasing the sugarconcentration without heating or crushing the cherries in the drums.

At the end of the run, the drums of maraschino cherries are stoodupright and disconnected from the system. The drum heads 39 andconnections are removed, the removable dividers are pulled out and thedrums of finished cherries, together with the syrup content are scaledup with standard drum heads ready for weighing and shipping.

The deposition of the sugar in the cherries and the cir culation takesplace automatically, and the syrup in contact with the cherries in thedrums replaces the moisture or water content of the cherries with thesugar solution. This replaced water dilutes the syrup moving upwardly ineach drum, so that automatic flow in the system is achieved because ofthe lower density of the solution in the lines 20, 22, 24, 26 and 28 andheating chamber 30 than in the lines 12, 14 and 16. In each drum thesaturated sugar solution flows down along the inclined bottom of thedrum and diffuses upwardly through the cherries in the lowercompartment, then through the lower perforated shelf and the layer ofcherries in the intermediate compartment and finally through the upperperforated shelf and the layer of cherries in the upper compartment ofthe drum. The perforated plate shelves 49 and 42 provide threerelatively thin layer-like bodies of cherries in each drum, therebyfacilitating distribution of the syrup upwardly through the layers ofcherries and preventing crushing and matting of the cherries.

The heating of the solution in the chamber 30 to a temperature of fromto l40 F. not only releases the air content of the solution butdecreases the density of the column flowing toward the chamber 10. Whilethe heating in the chamber 30 may be discontinued after the solutionbecomes clear in the chamber 10, it is, however, preferably continued tofacilitate the flow by increasing the difference in specific gravity ofthe two columns of liquid in the system. After the process is onceinitiated, it requires no attention whatever for the full period of therun, except to occasionally empty a 100 lb. bag of granulated sugar ontothe screen 46.

Example In a specific example of an operation for the production ofmaraschino cherries, seventeen (17) drums of cherries were connectedinto the connecting lines of the system, in which the liquid level inthe chamber 10 was l feet above the bottoms of the drums 18. Thecherries used in this run were pretreated in the usual manner for theproduction of maraschino cherries, including the treatment with sulphurdioxide brine, the pitting of the cherries and final washings to produceclean cherries free of sub phur dioxide. The cherries subjected to theprocess after pretreatment contained no sugar and they were drained andfilled into the drums after inserting the perforated shelves. Each drumwas filled with 367 lbs. of drained cherries for a total of 6,239 lbs.for the run.

After the seventeen (l7) filled drums were connected into the lines, thesystem, including the drums, was filled with water and the cherries wereprocessed for a period of 12 days in accordance with the proceduredescribed above. At the end of that time the maraschino cherriesproduced in the drums were weighed, giving a total weight of 7,286 lbs.for a net gain of 1,047 lbs., or a gain of approximately 16 /z%. Thesugar solids content of the cherries was approximately 45%, and thecherries were round, plump and firm and had an excellent appearance andcolor. The texture of the cherries was crisp, firm and tender.

The net gain of approximately 16%, as reported in the above example, isin contrast to the usual increase of only a few percent in conventionalprocesses of manufacturing maraschino cherries, in which a processingperiod of about 6 weeks is used. The increased yield obtained and theexceptional quality of the maraschino cherries produced may be theresult of the combination of conditions employed, particularly theeffective removal of air from the fruit in the initial stages of theprocess and the use of an air-free solution for syruping the fruit. Theheating of the solution returning to the chamber from 130 to 150 F.effectively removes the air content of the returning solution, and thesolution in the chamber 10 is maintained in a quiet unagitated conditionso that no air is taken up in dissolving the sugar. The heated solutionis at the top of the chamber and therefore eddying currents in thechamber are avoided. At the same time the sugar dissolves gradually inthe warm solution at the top of the chamber and gravitates slowly ascirculation proceeds. The air content of the cherries including that inthe tissues is effectively removed, thereby increasing the tissue spaceavailable for receiving the sugar solids from the solution.

The pressure effects achieved in the system in connection with thetemperatures and syrup concentrations employed are also regarded asimportant in obtaining the results reported above. In the first instancethere is the osmotic pressure of the sugar solution applied against thetissues of the fruit. In the process this pressure is kept low by slowlyand imperceptibly increasing the strength of the syrup at a rate naturalto the cherries, so that the sugar solids content of the cherries isnever more than 2% behind that of the syrup brought in contact with thecherries. The tissues of the cherries are, therefore, not broken and thecherry structure is maintained. In the second place there is a pressureeffect caused by the buoyancy of the cherries in the syrup, particularlyin the initial stages of the process when the cherries have a con less.The very small difference of only about 2% in sugar solids between thesyrup and cherries also reduces the buoyancy, which might be very greatwhere there is a great differential between the sugar solids in thecherries and syrup.

The air in the cherries, particularly in the initial stages of theoperations tends to increase the buoyancy of the cherries which mightunder other circumstances cause them to float to the top of the layer,but the liquid column in the system, for example 15 feet high, creates apressure effect of approximately 7 lbs. above atmospheric pressure inthe drums. This compresses the air initially in the cherries, so thatthe volume is greatly reduced and correspondingly reduces the buoyancyof the cherries. The air in the cherries is gradually dissolved andreplaced in the manner described above by the air-free syrup penecrating the cherries. The process is a gentle osmotic exchange whichleast alfects the cells and tissues of the cherries. Although theprocess is gentle, it is so thorough, rapid and complete in removing theair from the cavities and cell tissues that the finished cherries appeartranslucent as though candied. However, no heat had been applied in theprocess.

Experience in the operation of the process has shown that an increase inweight of approximately 16% is obtainable for cherries processed tobetween and sugar, while cherries processed to higher sugar contentsshow correspondingly higher yields.

It is to be understood that the process of the present invention may becarried out in apparatus somewhat differently arranged from thatdescribed, so long as the pressure, temperature and air removal featuresare employed in connection with the differential gravity flow system.However, the drums with removable heads are preferably used because ofthe convenience in handling, charging and preparing for shipment.

I claim:

1. An apparatus for syruping fruits for the production of preservedfruits comprising a solution chamber, a plurality of drums for holdingthe fruit to be syruped, means for conducting syrup in parallel from thelower portion of the solution chamber to the lower portion of the drums,a syrup heater, means for conducting syrup from the upper portion of thedrums in parallel into the heater, a screen in the upper portion of thesolution chamher for receiving granulated sugar, and means forconducting heated syrup from the syrup heater into the upper portion ofthe solution chamber.

2. An apparatus for the manufacture of preserved fruits containingdeposited sugar, in which the fruit after being prepared for syruping iscontacted with a sugar solution to deposit sugar in the fruit, theapparatus comprising a solution chamber for producing and holding asugar solution, a plurality of drums arranged in parallel for holdingbodies of fruit, means connecting the drums in parallel for syrup flowfrom and the solution chamber including means for conducting streams ofsolution in parallel from the solution chamber to the bottoms of thedrums thereby causing it to flow upwardly through the bodies of fruittherein to dissolve air and moisture from the fruit, said conductingmeans also including means for passing streams of solution from theupper portions of the drums and delivering the solution into the upperportion of the body of solution in the solution chamber, means forheating the solution flowing from the drums to the solution chamber, andmeans dividing each drum into a plurality of superposed compartmentseach for holding a relatively shallow body of fruit.

3. An apparatus for the manufacture of preserved fruits containingdeposited sugar, in which the fruit after being prepared for syruping iscontacted with a sugar solution to deposit sugar in the fruit, theapparatus comprising a solution chamber for producing and holding asugar solution, a container for holding a body of fruit to be syruped,means connecting the lower portion of the container with the lowerportion of the chamber for conducting a stream of sugar solution fromthe chamber to the container, means for conducting sugar solution fnomthe upper portion of the container into the upper portion of thesolution chamber, and means for heatin the sugar solution flowing fromthe container to the solution chamber for the liberation of air from thesolution flowing to the solution chamber.

4. An apparatus as claimed in claim 3, in which the solution chamber islocated at an elevation higher than that of the fluit containersufficiently to provide a pressure head approximately seven pounds persquare inch in the fruit container.

5. An apparatus as claimed in claim 3, in which the container is a drummounted approximately horizontal, and a grid structure located in thedrum comprising spaced perforated plates dividing the drum intosuperposed compartments for holding fruit.

6. An apparatus for the manufacture of preserved fruits containingdeposited sugar, in which the fruit after being prepared for syruping iscontacted with a sugar solution to deposit sugar in the fruit, theapparatus comprising a solution chamber for producing and holding asugar soluto tion, a plurality of drums arranged in parallel for holdingbodies of fruit, 21 pair of headers respectively connected into theupper and lower portions of the solution chamber, a solution fiowconnection connecting the upper portion of each drum with the headerconnected into the upper portion of the solution chamber, a solutionflow connection connecting the lower portion of each drum with theheader connecting the lower portion of each drum with the headerconnected into the lower portion of the solution chamber, a valve ineach of said connections, and said solution flow connections beingreadily connectable and disconnectable from the drums.

7. An apparatus as claimed in claim 6, in which each drum is providedwith a readily removable head through which the connections for the drumextend.

References Cited in the file of this patent UNITED STATES PATENTS 66,208Brooks July 2, 1867 2,236,692 Neil Apr. 1, 1941 2,785,071 Mathews Mar.12, 1957

1. AN APPARATUS FOR SYRUPING FRUITS FOR THE PRODUCTION OF PRESERVEDFRUITS COMPRISING A SOLUTION CHAMBER, A PLURALITY OF DRUMS FOR HOLDINGTHE FRUIT TO BE SYRUPED, MEANS FOR CONDUCTING SYRUP IN PARALLEL FROM THELOWER PORTION OF THE SOLUTION CHAMBER TO THE LOWER PORTION OF THE DRUMS,A SYRUP HEATER, MEANS FOR CONDUCTING SYRUP FROM THE UPPER PORTION OF THEDRUMS IN PARALLEL INTO THE HEATER, A SCREEN IN THE UPPER PORTION OF THESOLUTION CHAMBER FOR RECEIVING GRANULATED SUGAR, AND MEANS FORCONDUCTING HEATED SYRUP FROM THE SYRUP HEATER INTO THE UPPER PORTION OFTHE SOLUTION CHAMBER.